The effect of vanadium doping on the cycling performance of LiNi0.5Mn1.5O4 spinel cathode for high voltage lithium-ion batteries

High voltage LiNi0.5Mn1.5O4 (LMNO) spinel cathode has been attracting high interest due to its high energy density and cobalt-free chemistry. However, high temperature (50 °C) cycling behavior is not very good because of the electrolyte decomposition, metal dissolutions, and the formation of gas products. To improve the high-temperature cycling behavior of the LMNO spinel cathode, vanadium doping was employed. For this purpose, pristine LMNO, LiNi0.45Ti0.1Mn1.45O4, and LiNi0.4V0.1Mn1.5O4 cathode materials were synthesized and their elevated temperature cycling behavior was compared. After 200 cycles, the 10% V-doped LMNO still has an excellent cycling performance of 99.5 mAh g−1 (capacity fade is 6.55%) at 50 °C and 1C-rate compared to 28.8 mAh g−1 pristine LMNO (capacity fade is 70.4%), and 84 mAh g−1 LiNi0.45Ti0.1Mn1.45O4 capacity retention (capacity fade is 25.6%), respectively. These results showed that the V-doped LMNO design is the proper solution for high-temperature durability.